fix(mcp): project reads list milestones without their plans, and cap done ones (#4045)

enter_project returned every milestone's full plan body. On a project with 39
milestones the handshake came to ~222k characters, 168k of them bodies (110k
from done milestones). That is past what an MCP client accepts as a tool
result, so the call meant to orient a session arrived as a file to page
through. It grows with a project's history, so any long-lived project on any
install gets there.

- brief_milestone_summary (services/milestones.py) trims summary rows to the
  listing fields: id, title, description, status, order_index and progress.
  The plan is get_milestone's job. user_id, project_id and timestamps repeat
  what the caller knows.
- enter_project and get_project share one block: every open milestone plus
  the 5 most recently updated done ones, in order. milestone_summary_omitted
  is attached only when older done ones were left out, and names
  list_milestones and get_milestone.
- list_milestones lists every milestone, done included, without bodies. It is
  the call the omitted line points to, and it had the same size problem.
- The REST project summary is unchanged; the web UI reads it.

Tests: trimming, the done cap and its order, the omitted key present and
absent, get_project and list_milestones, and a size ceiling on enter_project's
milestone block for a 200-milestone history.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01821k5B3Ysecp9fNYs92Kuy

src/scribe/mcp/tools/milestones.py

@@ -22,12 +22,15 @@ from scribe.services.record_refs import refuse_guessed_ids
 async def list_milestones(project_id: int) -> dict:
     """List milestones for a Scribe project, ordered by order_index.
 
-    Returns id, title, description, body (the plan/design), status
-    (active/done), order_index, and task counts.
+    Returns every milestone, done ones included: id, title, description,
+    status (active/done), order_index and progress (total, completed, pct,
+    status_counts). The plan itself is not listed: get_milestone(id) returns a
+    milestone's body and its steps.
     """
     uid = current_user_id()
     rows = await milestones_svc.get_project_milestone_summary(uid, project_id)
-    return {"milestones": rows}
+    brief, _ = milestones_svc.brief_milestone_summary(rows)
+    return {"milestones": brief}
 
 
 async def get_milestone(milestone_id: int) -> dict:

src/scribe/mcp/tools/projects.py

@@ -42,6 +42,32 @@ async def list_projects() -> dict:
     return {"projects": [p.to_dict() for p in rows]}
 
 
+# Done milestones a project read still lists: the recent ones say what just
+# finished, and older ones are a list_milestones call away (#4045).
+_DONE_MILESTONES_KEPT = 5
+
+
+async def _milestone_block(uid: int, project_id: int) -> dict:
+    """`milestone_summary` for a project read, brief and bounded (#4045).
+
+    Every open milestone plus the most recent done ones, without plan bodies.
+    `milestone_summary_omitted` is attached only when older done milestones
+    were left out, and names the calls that reach them (#2483).
+    """
+    rows = await milestones_svc.get_project_milestone_summary(uid, project_id)
+    brief, omitted = milestones_svc.brief_milestone_summary(
+        rows, done_kept=_DONE_MILESTONES_KEPT,
+    )
+    out: dict = {"milestone_summary": brief}
+    if omitted:
+        out["milestone_summary_omitted"] = (
+            f"{omitted} older done milestone(s) not listed. "
+            f"list_milestones({project_id}) lists every milestone; "
+            "get_milestone(id) has one milestone's plan and steps."
+        )
+    return out
+
+
 async def enter_project(project_id: int) -> dict:
     """Session-start handshake: load full context for working on a project.
 
@@ -63,6 +89,11 @@ async def enter_project(project_id: int) -> dict:
     open_tasks, recent_notes, design_system, systems, pattern_coverage —
     plus systems_bootstrap, present only when it applies (see below).
 
+    `milestone_summary` lists every open milestone and the most recently
+    finished done ones, each with its description and progress but NOT its
+    plan: get_milestone(id) reads a plan. `milestone_summary_omitted` appears
+    only when older done milestones were left out, and says how many.
+
     `pattern_coverage` (usually null) is the shape-accounting line — how many
     of the bound repo's extracted shapes carry a classification against canon
     (note 2786) — e.g. "shape accounting: 3100/4573 shapes accounted for —
@@ -120,9 +151,7 @@ async def enter_project(project_id: int) -> dict:
     applicable = await rulebooks_svc.get_applicable_rules(
         project_id=project_id, user_id=uid,
     )
-    milestone_summary = await milestones_svc.get_project_milestone_summary(
-        uid, project_id,
-    )
+    milestones = await _milestone_block(uid, project_id)
     open_tasks, _ = await notes_svc.list_notes(
         uid, is_task=True, project_id=project_id,
         status=["todo", "in_progress"], sort="updated_at", limit=10,
@@ -206,7 +235,7 @@ async def enter_project(project_id: int) -> dict:
             for s in systems
         ],
         "design_system": design_system,
-        "milestone_summary": milestone_summary,
+        **milestones,
         **rulebooks_svc.rules_payload(applicable, user_id=uid, source="enter_project"),
         "open_tasks": [
             {
@@ -236,8 +265,10 @@ async def enter_project(project_id: int) -> dict:
 async def get_project(project_id: int) -> dict:
     """Fetch a Scribe project by ID.
 
-    Returns full project fields, a milestone_summary list, and the
-    rulebook-applicable_rules / subscribed_rulebooks pair the assistant
+    Returns full project fields, a milestone_summary list (shaped as in
+    enter_project: open milestones and the recent done ones, no plan bodies,
+    with milestone_summary_omitted when older done ones were left out), and
+    the rulebook-applicable_rules / subscribed_rulebooks pair the assistant
     should consult when working on this project.
     """
     uid = current_user_id()
@@ -245,9 +276,7 @@ async def get_project(project_id: int) -> dict:
     if project is None:
         raise ValueError(f"project {project_id} not found")
     data = project.to_dict()
-    data["milestone_summary"] = await milestones_svc.get_project_milestone_summary(
-        uid, project_id,
-    )
+    data.update(await _milestone_block(uid, project_id))
     applicable = await rulebooks_svc.get_applicable_rules(
         project_id=project_id, user_id=uid,
     )

src/scribe/services/milestones.py

@@ -238,3 +238,38 @@ async def get_project_milestone_summary(user_id: int, project_id: int) -> list[d
     """Ordered milestones with progress — the one-project view of
     get_project_milestone_summaries (two queries, not N+1)."""
     return (await get_project_milestone_summaries(user_id, [project_id])).get(project_id, [])
+
+
+# What a milestone LISTING needs: enough to say what each plan is and how far
+# along it is. The plan itself (`body`) is get_milestone's job. Summaries once
+# carried it, and on a project with 39 milestones enter_project came to ~222k
+# characters, 168k of them plan bodies. That is past what an MCP client will
+# accept as a tool result, so the session handshake arrived as a file to page
+# through (#4045). user_id / project_id / timestamps repeat what the caller
+# already knows.
+_BRIEF_FIELDS = (
+    "id", "title", "description", "status", "order_index",
+    "total", "completed", "pct", "status_counts",
+)
+
+
+def brief_milestone_summary(
+    rows: list[dict], *, done_kept: int | None = None,
+) -> tuple[list[dict], int]:
+    """Trim summary rows to the listing fields, optionally capping done ones.
+
+    `done_kept` keeps only the N most recently updated done milestones (every
+    open one stays), in the original order_index order. A done plan is
+    history, and a handshake that grows with a project's whole history grows
+    past what a client accepts. None keeps every row. Returns (rows, omitted),
+    where `omitted` counts the done milestones left out.
+    """
+    if done_kept is None:
+        kept = rows
+    else:
+        done = [r for r in rows if r.get("status") == "done"]
+        recent = sorted(done, key=lambda r: r.get("updated_at") or "", reverse=True)
+        keep_ids = {r.get("id") for r in recent[:done_kept]}
+        kept = [r for r in rows if r.get("status") != "done" or r.get("id") in keep_ids]
+    brief = [{k: r[k] for k in _BRIEF_FIELDS if k in r} for r in kept]
+    return brief, len(rows) - len(kept)